We are interested at looking at the impact of sudden stratospheric warmings on the troposphere. We are wondering if there is a nudging capacity in OpenIFS so that we could force the stratosphere to be "correct" (i.e. nudge towards reanalysis) and then focus on the downward propagation? I had a quick look in the code and found some flags relating to nudging (e.g in yomlsfoc.F90 and in updti.F90) but I couldn't figure out the details. Any information about if this is possible and how to do this would be appreciated.

12 Comments

  1. Unknown User (nagc)

    Hi Victoria,

    There is a nudging capability that's in use for research here. I am not sure what is available in OpenIFS, or whether what's there works.

    We'll investigate and get back to you.

    Regards,   Glenn

  2. Marcus Koehler

    Hi Victoria,

    As Glenn already wrote, nudging to reanalyses in OpenIFS is something that we intend to look into early in the new year, as nudging has been used in the IFS before.  We will check what's possible and will get back to you as soon as we have some answers.

    Regards,  Marcus

  3. Etienne Tourigny

    Reviving another thread - is nudging now available in openifs 43r3?  I know this feature was back-ported to the ancient IFS used in EC-Earth some time ago.

    1. Unknown User (nagc)

      Yes, nudging is available in OpenIFS 43r3 and Marcus has tested it. There are various ways of nudging however and it depends whether the code supports how you like to do your nudging.


  4. Vladimir Lapin

    Hi, if I may to hijack this thread... 

    In this article How to use OpenIFS in nudged configuration by  Marcus Koehler, it is suggested that from OpenIFS 43r3v1 it is possible to specify the directory for the nudging files using these path variables: CSPSHRLX and CSPGGRLX.I looked at the namelist and the source code  src/ifs/utility/updrlxref.F90. But these path variables are not there. We have OpenIFS 43r3v1. 

    Our runtime directory is already quite busy and the amount of nudging files can make it overwhelming for the user to do anything there. Could you clarify whether it is just a matter of having the wrong version?

  5. Marcus Koehler

    Hi Vladimir Lapin, 

    Thank you for posting. The two variables are called CLPSHRLX and CLPGGRLX (not CSP...).  There was indeed a typo in the early paragraph of the Confluence page, however further below on the same page where the setup is described the correct names are used.  You will find that both variables are being used in updrlxref.F90 as they should be.  I have now corrected this error on the Confluence page and it is now consistent, thank you for pointing it out.

    Regards, Marcus

  6. Vladimir Lapin

    Hi Marcus Koehler,

    Thank you for a very prompt reply. Oh, I did not notice the typo in my message (which indeed was taken from your guide). Thank you for the correction but, unfortunately, it was not an issue of a bad search.  For example, this is our namrlx.nam.h.

    ! ------------------------------------------------------------
    NAMELIST/NAMRLX/&
    & LRLXG, NFRLXG &
    & , LRLXVO, LRLXDI, LRLXTE, LRLXQ, LRLXLP &
    & ,LRLXQI,LRLXQL,LRLXQC,LRLXO3 &
    & , XRLXVO, XRLXDI, XRLXTE,XRLXQ, XRLXO3, XRLXLP &
    & , ALATRLX1, ALATRLX2, ALONRLX1, ALONRLX2 &
    & , NRLXLMIN, NRLXLMAX, NRLXLMINU, NRLXLMAXU, AXRLX ,AYRLX ,AZRLX &
    & , NRLXSMAX

    It contains ozone relaxation flags (e.g. LRLXO3) which are not in the older cycles of openifs but it does not contain CLPSHRLX. The same is true for  updrlxref.F90. I am also trying to ask around internally at BSC why our 43r3v1 code could be different. But I would appreciate if you could double-check it on your side as well. Many thanks!

  7. Vladimir Lapin

    I just want to confirm it is indeed a problem with the source code that we currently have and that it needs to be updated to the released version OpenIFS 43r3v1. No action needed. Thank you again, Marcus.

  8. Etienne Tourigny

    I think the confusion came because Vladimir was looking at openifs in the EC-Earth4 code which hasn't yet been updated to 43r3v1 yet...  We have a proper copy of the latest standalone version of openifs at BSC.

  9. Vladimir Lapin

    yes, thanks for the clarification, Etienne

  10. Marcus Koehler

    OK, thanks Etienne Tourigny and Vladimir Lapin for checking this. The standalone OpenIFS 43r3v1 available from our ftp server contains all the modifications that are needed for including the path variables.

    Best, Marcus

  11. Unknown User (nagc)

    I think BSC also took a beta-release version of OpenIFS 43r3v1 before it was fully released, that might explain it.